1. Field of the Invention
The present invention relates to assistive hearing devices. More specifically, the present invention relates to a hearing aid mounted internally to an ear.
2. Background of the Related Art
Hearing devices are well known and typically include a microphone, an amplifier and a speaker. Typically, the microphone receives a sound wave and converts the wave into an electrical signal, the amplifier amplifies the electrical signal, and the speaker converts the amplified signal into amplified sound waves that impart vibrations to the tympanic membrane or ear drum in the ear. Common hearing aids are mounted outside the ear canal, particularly around the outer ear. The externally mounted hearing aid has the advantage of accessibility to change batteries and to adjust the volume of sound. However, many users find such externally mounted hearing aides relatively bulky and objectionable for cosmetic reasons.
An alternative to externally mounted hearing aides are internally mounted hearing aids disposed in an ear canal of a user. Such internally mounted hearing aides offer better cosmetic appearance, but have disadvantages as well. For instance, the typical internally mounted hearing aid blocks the majority, if not all, of the ear canal diameter. Such blockage can cause the body of the user to produce an excessive amount of ear wax in the ear canal and can cause ear infections. Further, the blocking of the ear canal obstructs the natural transmission of sound waves through the ear canal that impact the tympanic membrane. Unless a user is totally hearing impaired, any ability of the tympanic membrane to register the natural occurring sound waves is reduced or eliminated. Thus, the user is substantially dependent upon the sound fidelity of the hearing aid. Still further, the typical internally mounted hearing aids may still be visible in the ear canal by peering at the head of the user from the side.
Some hearing systems deliver audio information to the ear through electromagnetic transducers. A microphone and amplifier transmit an electronic signal to a transducer that converts the electronic signal into vibrations. The vibrations vibrate the tympanic membrane or parts of the middle ear that transmits the sound impulses without reconverting to audio sound waves from a speaker. A separate magnet can be remotely mounted at or near the tympanic membrane. The interaction between the magnetic fields of the transducer receiving the electronic signal and the magnet mounted at or near the tympanic membrane causes the magnet to vibrate and thus mechanically transmits the sound through the vibration to the ear. Typically, however, the remainder of the hearing aid is inserted into the ear canal or on the outer ear and can cause to the problems discussed above. Still further, the transducers and/or magnets of the hearing aids are mounted in a relatively invasive procedure. For instance, one contact transducer having a magnet is installed by cutting through the tympanic membrane, microscopically drilling bone structure and screwing the magnet to the malleus of the ossicular chain in the middle ear. Such procedures are expensive and can be painful.
Therefore, there remains a need for a relatively compact hearing aid that can be inserted in the ear canal and/or through the tympanic membrane using simplified surgical procedures and that can be hidden from external view.
The present invention provides an apparatus and method for inserting a relatively compact hearing aid at least partially through the tympanic membrane using a simplified surgical procedure. The hearing aid includes a microphone, an amplifier, and at least one speaker that can be assembled into a single enclosure for insertion through the tympanic membrane. The simplified surgical procedure can be performed on an outpatient basis and generally includes anesthetizing a portion of the tympanic membrane, forming an incision with a cutting instrument in the tympanic membrane and inserting the hearing aid at least partially therethrough. Incisions and placement of a tube in an tympanic membrane for ear drainage is routinely performed in pediatric patients and combines low morbidity and good patient tolerability. The tympanic membrane restrains the hearing aid in position for at least a period of time. A power source, such as a battery, powers the hearing aid. Further, a receiver may be included with the hearing aid and can control the hearing aid from external sources. The receiver can control the amplified volume, receive sound transmissions from the opposite ear or a hearing aid in the opposite ear or receive personal communications.
In one aspect, the invention provides an apparatus for enhancing hearing, comprising a microphone, an amplifier coupled to the microphone, a speaker coupled to the amplifier, the microphone, the amplifier and the speaker being connected to each other and insertable at least partially through a tympanic membrane of a user. In another aspect, the invention provides a method of inserting a hearing aid into an ear comprising inserting a cutting device into an ear, forming an incision in a tympanic membrane, and inserting a hearing aid comprising a microphone, an amplifier and a speaker at least partially through the tympanic membrane.